Stop Freq

Sets the frequency at the right side of the graticule. While adjusting Stop Freq, Start Freq is held constant, which means that both Center Frequency and Span will change.

Stop Freq also sets the frequency entry mode to Start or Stop. In Start or Stop mode, the start frequency and stop frequency values are displayed below the graticule, and the default active function in the Frequency menu is Start Freq.

Remote Command

[:SENSe]:FREQuency:STOP <freq>

[:SENSe]:FREQuency:STOP?

Example

:FREQ:STOP 220 MHz

:FREQ:STOP?

Notes

Preset and Max values depend on Hardware Options

Dependencies

By direct entry:

You cannot set Start Freq > Stop Freq
You cannot set Start Freq = Stop Freq
You cannot select Zero Span by setting Start Freq = Stop Freq
You cannot set Start Freq to a value that would create a span of less than 10 Hz

If you try to do any of the above, Stop Freq changes to maintain a minimum of 10 Hz for the difference between Start Freq and Stop Freq

With the knob or step keys:

You cannot increment Start Freq to a value greater than Stop Freq – 10 Hz. If already in Zero Span, you cannot increment at all, and the first decrement is forced to at least 10 Hz

Stop Freq can be limited by Span limits, if Start Freq is above its preset value

If the electronic/soft attenuator is enabled, any attempt to set Stop Freq >3.6 GHz fails and results in an advisory message. If the equivalent SCPI command is sent, this same message is generated as part of a “-221, Settings conflict” warning

If Source Mode is set to Tracking, and the Max or Min Start Freq is therefore limited by the limits of the source, a warning message is generated, “Data out of range; clipped to source max/min” if these limits are exceeded. Note that for an external source, these limits can be affected by the settings of Source Numerator, Source Denominator, and Power Sweep

Couplings

The four parameters Center Frequency, Start Freq, Stop Freq and Span are interdependent, as changing one necessarily affects one or more of the others. The couplings between Center Frequency and Span are detailed under the control descriptions for those controls. These couplings also affect Start Freq and Stop Freq

Preset

On Mode Preset, Span and Center Frequency preset, and Stop Freq is derived. See Center Frequency Presets in Center Frequency for the Stop Freq after Preset for various model and option numbers

On Meas Preset, only Span presets, but Center Frequency does not, so Stop Freq will vary depending on Center Frequency

When Mode Preset is performed while in External Mixing, the Stop Freq of the current Mode is set to the nominal Max Freq of the highest harmonic range in the Harmonic Table for the current mixer setup

If the current measurement has a limited Span available to it, and cannot achieve the Span shown in the table (Span = Stop Freq – Start Freq), the instrument uses the maximum Span the measurement allows, and sets Center Frequency to the midpoint of the Start Freq and Stop Freq values in the Harmonic Table. Thus, in this case, Stop Freq presets to a frequency above the preset Center Frequency by ½ of the maximum Span

When Restore Input/Output Defaults is performed, the mixer presets to the 11970A, whose Stop frequency is 40 GHz

Therefore, after Restore Input/Output Defaults, if you switch to External Mixing and do Mode Preset while in the Spectrum Analyzer Mode, the resulting Stop Freq is 40 GHz

State Saved

Saved in instrument state

Min

-79.999990 MHz, unless Source Mode is set to Tracking, in which case it is limited by the minimum frequency of the Source

Instrument Types	Min Value
VXT models M9421A	55.000010 MHz
VXT models M9410A/11A/15A/16A	330.000010 MHz 6.510 kHz with Option LFE
VXT model M941xE (VXT model M941xA associated with M9471A) RF port on S9110E	330.000010 MHz 750.010 kHz with Option LFE
RRH Port on S9110E	22.700000010 GHz
M8920A	80.010 kHz

If the knob or step keys are being used, depends on the value of the other three interdependent parameters

While in External Mixing, the minimum Stop Freq you can set is determined by the external mixing parameters. It will be close to the minimum LO frequency (3.8 GHz if undoubled, 8.6 GHz if doubled) times the harmonic number, for the lowest harmonic range in the Harmonic Table for the current mixer setup. It can be queried with :FREQ:STOP? MIN

Max

Depends on instrument maximum frequency. Note that, if Source Mode is set to Tracking, the effective instrument maximum frequency may be limited by the source maximum frequency

If the knob or step keys are being used, depends on the value of the other three interdependent parameters

While in External Mixing, the maximum Stop Freq you can set is determined by the external mixing parameters. It will be close to the maximum LO frequency (7 GHz if undoubled, 14 GHz if doubled) times the harmonic number, for the highest harmonic range in the Harmonic Table for the current mixer setup. It can be queried with :FREQ:STOP? MAX

Annotation

Stop <value> appears in the lower right corner of the display. This replaces Span <value>

Status Bits/OPC dependencies

Non-overlapped